What is a 13.5 mm drill in decimal and mm?

0.5315 in, or 13.500 mm; nearest fractional drill: 17/32" (0.5313 in, -0.0003 in); nearest number / letter drill: Letter Z (0.4130 in, -0.1185 in).

What RPM for a 13.5 mm drill in steel?

In low-carbon steel (1018) an HSS 13.5 mm drill (0.5315 in) runs about 650 RPM at 90 SFM; a carbide drill about 2,160 RPM at 300 SFM. RPM = 3.82 × SFM ÷ D.

What feed for a 13.5 mm drill?

About 0.0106 in/rev in mild steel, 0.0101 in/rev in aluminum and 0.0086 in/rev in 304 stainless. At 650 RPM that is 6.89 IPM in steel (IPM = RPM × IPR).

What RPM for a 13.5 mm drill in aluminum?

1,800 RPM with HSS (250 SFM) or up to 4,310 RPM with carbide (600 SFM), feeding about 0.0101 in/rev.

What size is a 13.5 mm drill?

0.5315 in / 13.50 mm. The nearest other drills are 17/32" (0.5313 in), 13.6 mm (0.5354 in), 13.4 mm (0.5276 in).

13.5 mm drill size

A 13.5 mm metric drill is 0.5315 in (13.500 mm).

Decimal inch: 0.5315
Millimeters: 13.500
Nearest 1/64: 17/32" (+0.0002)
Type: metric drill

Nearest equivalents in other systems

Drills closest to 13.5 mm
System	Drill	Inch	mm	Difference
Fractional	17/32"	0.5313	13.494	-0.0003 in
Number / letter	Letter Z	0.4130	10.490	-0.1185 in

Speeds and feeds: in mild steel an HSS drill starts at about 650 RPM and 0.0106 in/rev (6.89 IPM); in 6061 aluminum about 1,800 RPM.

13.5 mm drill speeds and feeds by material

Jobber-length twist drill, D = 0.5315 in. RPM = 3.82 × SFM ÷ D, rounded to 10. Feed per rev scales with diameter and material; IPM = RPM × IPR.

13.5 mm drilling speeds
Material	HSS SFM	HSS RPM	Carbide SFM	Carbide RPM	Feed (in/rev)	HSS IPM	Carbide IPM
Aluminum (6061)	250	1,800	600	4,310	0.0101	18.2	43.5
Brass / free-machining	150	1,080	400	2,870	0.0083	8.96	23.8
Low-carbon steel (1018)	90	650	300	2,160	0.0106	6.89	22.9
Alloy steel (4140, annealed)	70	500	250	1,800	0.0116	5.80	20.9
Stainless 304	40	290	150	1,080	0.0086	2.49	9.29
Gray cast iron	80	570	250	1,800	0.0087	4.96	15.7
Titanium 6Al-4V	25	180	100	720	0.0051	0.92	3.67
Plastics (acetal)	300	2,160	500	3,590	0.0061	13.2	21.9

Metric: Vc (m/min) = SFM × 0.3048; feed (mm/rev) = in/rev × 25.4. In steel, 650 RPM × 0.269 mm/rev = 175 mm/min.

Worked example: 13.5 mm drill in 1018 steel

HSS drill in low-carbon steel: 90 SFM.
RPM = 3.82 × 90 ÷ 0.5315 ≈ 650 RPM.
Feed for a 0.531 in drill in mild steel ≈ 0.0106 in/rev.
IPM = 650 × 0.0106 = 6.89 IPM.

Peck cycle by hole depth

13.5 mm drill: depth and canned cycle
Depth	Cycle	Peck	Note
3×D = 1.595 in (40.5 mm)	G81 (no peck)	None	Up to 3×D a sharp drill clears chips on its own.
5×D = 2.657 in (67.5 mm)	G73 chip-break	1 × D	Chip-break pecks; full retract if chips pack (soft aluminum, stainless).
8×D = 4.252 in (108 mm)	G83 full retract	0.5-1 × D, shrinking with depth	Retract to clear chips; reduce feed ~10-20% past 5×D.

Taps that use a 13.5 mm drill

No standard UNC, UNF or metric tap in our tables calls for a 13.5 mm drill. Use it for clearance, pilot or reamer prep holes.

Nearest drills

17/32": 0.5313 in / 13.494 mm (-0.0003 in)
13.6 mm: 0.5354 in / 13.600 mm (+0.0039 in)
13.4 mm: 0.5276 in / 13.400 mm (-0.0039 in)
13.7 mm: 0.5394 in / 13.700 mm (+0.0079 in)

Drill speed calculator, prefilled for 13.5 mm Drill finder: sizes near 13.5 mm Metric drill chart Decimal equivalent chart

Common questions

What is a 13.5 mm drill in decimal and mm?: 0.5315 in, or 13.500 mm; nearest fractional drill: 17/32" (0.5313 in, -0.0003 in); nearest number / letter drill: Letter Z (0.4130 in, -0.1185 in).
What RPM for a 13.5 mm drill in steel?: In low-carbon steel (1018) an HSS 13.5 mm drill (0.5315 in) runs about 650 RPM at 90 SFM; a carbide drill about 2,160 RPM at 300 SFM. RPM = 3.82 × SFM ÷ D.
What feed for a 13.5 mm drill?: About 0.0106 in/rev in mild steel, 0.0101 in/rev in aluminum and 0.0086 in/rev in 304 stainless. At 650 RPM that is 6.89 IPM in steel (IPM = RPM × IPR).
What RPM for a 13.5 mm drill in aluminum?: 1,800 RPM with HSS (250 SFM) or up to 4,310 RPM with carbide (600 SFM), feeding about 0.0101 in/rev.
What size is a 13.5 mm drill?: 0.5315 in / 13.50 mm. The nearest other drills are 17/32" (0.5313 in), 13.6 mm (0.5354 in), 13.4 mm (0.5276 in).

Nearby drill sizes

Sources

Machinery's Handbook, 31st ed., Speeds and Feeds for Drilling, Reaming and Threading (Tables 17-23) — HSS and carbide drilling SFM (rounded).
RedLine Tools (Productivity Inc.) catalog p. 340, Cobalt & HSS Drills Speeds & Feeds — feed per rev by drill diameter and material (middle of the catalog range).
ASME B94.11M twist drills: number (#1-#80) and letter (A-Z) drill sizes; drill size reference.

Material feed multipliers (aluminum 1.3×, brass 1.1×, 4140 0.85×, stainless and titanium 0.7× the mild-steel feed) are JobLine estimates. Peck guidance is JobLine shop practice. Use your drill maker's data first.

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